1. Field of the Invention
This invention relates to a railroad nipper-clipper and, more specifically, to a nipper-clipper that may adjust railroad ties laterally.
2. Background Information
A railroad track includes one or more pairs of longitudinal rails, a plurality of lateral ties, and a ballast bed. The ballast bed is made from large particulate materials, typically gravel. The ties rest on the ballast bed. The pairs of tracks are coupled to the ties. While rails have been traditionally coupled to wooden ties by spikes, modern concrete ties utilize a system of clip assemblies.
Railroad tie clip assemblies include a tie plate fixed to the tie and two springs. The tie plate extends to, or is bifurcated on, both sides of the rail, and the rail is disposed therebetween. Two springs are coupled to the tie plate, one disposed on each side of the rail. The springs have an upper U-shaped portion and two lower fingers that double back under the U-shaped portion. The spring biases the U-shaped portion towards the fingers. The fingers engage the tie plate and are horizontally slidable thereon. The springs move from an installed position where the U-shaped portion engages the rail to an uninstalled position where the U-shaped portion does not engage the rail. Thus, the U-shaped portion biases the rail against the tie plate, and, by extension against the tie.
A clipping machine, hereinafter a “clipper,” is a device structured to couple the rail to the tie by moving the spring from the uninstalled position to the installed position. Clippers are known in the prior art. A typical operation for a clipper occurs on a newly laid track, or a restored track, wherein the ballast bed has been laid, the ties installed thereon, and the rails disposed between the plurality of clip assemblies on the ties. So long as the rails are aligned in the tie plates, the clipper need only to advance along the track installing clips. If, however, the ballast bed is not smooth, certain ties may be lower than adjacent ties. In this situation the ties may have to be lifted in order to align the brackets with the rails. The act of lifting a tie to be in contact with the lower side of a rail is called “nipping.” The device structured to lift the tie is called a “nipper.” The nipping and clipping operations must be performed at the same time. Thus, the device that combines these features is a “nipper-clipper.”
Prior art nippers utilized one or more, typically two, clamps that gripped the forward and aft sides of a tie, or, extended over the forward and aft sides of the tie while lifting the tie from the underside. While the prior art nippers were effective in lifting the tie into contact with the underside of the rail, the prior art nippers could not laterally adjust the tie. That is, if the tie was laterally off center, as compared to the rails or adjacent ties, the prior art nippers had no means for laterally repositioning or adjusting the tie so that the rail would be centrally over the tie plate.
There is, therefore, a need for a nipper-clipper assembly structured to laterally adjust a tie.
There is a further need for a nipper-clipper assembly that automatically laterally adjusts a tie.
There is a further need for a mobile nipper-clipper vehicle structured to travel along a track laterally adjusting ties and installing clip assembly springs.